Anxiety disorders are the most commonly occurring disorders of the psychiatric illnesses and constitute an immense economic burden. In addition to generalised anxiety disorder, they encompass post-traumatic stress disorder (PTSD), panic disorder, obsessive compulsive disorder and social as well as other phobias.
PTSD can be severe and chronic, with some studies suggesting a lifetime prevalence of 1.3% to 7.8% in the general population. PTSD affects about 7.7 million American adults, but it can occur at any age, including childhood. Women are more likely to develop PTSD than men, and there is some evidence that susceptibility to the disorder may run in families. PTSD is often accompanied by depression, substance abuse, or one or more of the other anxiety disorders. PTSD typically follows a psychologically distressing traumatic event. These events may include military combat, terrorist incidents, physical assault, sexual assault, motor vehicle accidents, and natural disasters, for example. The response to the event can involve intense fear, helplessness, or horror. Most people recover from the traumatic event with time and return to normal life. In contrast, in PTSD victims, symptoms persist and may worsen with time, preventing a return to normal life. PTSD studies have reported evidence of increased inflammatory activity in the immune system, including higher levels of inflammatory cytokines both at baseline and following antigenic stimulation. These higher levels of inflammatory activity have been linked to HPA axis abnormalities and to alteration to serotonergic and noradrenergic metabolism. A chronically activated inflammatory response has been shown to exert adverse reactions on many body systems. Specifically, elevations of interleukin-6 (IL-6) have been associated with reports of chronic pain, arthritis, diabetes, cardiovascular disease, and other medical conditions that have been associated with PTSD. Indeed, patients with chronic PTSD have been shown to have significantly higher levels of IL-1β, IL-6, IL-8, TNF-alpha, and MCP-1, but in some cases lower C-reactive protein and lower soluble CD-40.
Psychotherapy is currently the backbone of PTSD treatment. Methods include cognitive-behavioural therapy, exposure therapy, and eye movement desensitization and reprocessing. Medication can enhance the effectiveness of psychotherapy. Selective serotonin reuptake inhibitors (SSRIs), such as sertraline (Zoloft®) and paroxetine (Paxil®), are the only medications approved for treating PTSD by the Food and Drug Administration. Many unwanted side-effects are associated with SSRI usage. These include concerns about drug interactions, gastrointestinal side-effects, sexual side-effects, suicidal ideation, acute anxiogenic effects, and slow onset of action. Some tricyclic antidepressants (TCAs) and monamine oxidase inhibitors (MAOIs) appear to have some efficacy but patient tolerance is low due to the high incidence of side-effects. MAOIs have dietary restriction requirements and are linked to hypertensive events. TCAs have anticholinergic and cardiovascular side-effects. Lamotrigine, a sodium channel blocker, has had some efficacy in treating PTSD in a small-scale placebo controlled study.
There is a need for the development of treatments or preventative therapies for PTSD that are safe and effective.